Snooty, the world’s oldest known captive manatee who lived at a South Florida aquarium for more than half a century, died on Sunday. He was 69.

Born in 1948, Snooty’s arrival was the first ever recorded manatee birth in human care. He moved to the South Florida Museum in Bradenton in 1949, and saw more than 1 million visitors during his lifetime.

Snooty was dubbed the official mascot for Manatee County in 1979, and celebrated his 69th birthday on Saturday.

The museum, which houses the Parker Manatee Aquarium, said Snooty died after getting trapped in an underwater area of his exhibit. Jeff Rodgers, the museum’s provost and chief operating officer, said Snooty was able to access an area of his exhibit that contained plumbing equipment after a hatch blocking it off “had somehow been knocked loose.” Three smaller manatees were able to swim in and out of the “tight area,” but Snooty swam in and became stuck.

Snooty was about twice the size of the other animals and weighed about 1,300 pounds, NPR reported.

“It took us some time to figure out how we were going to deal with that situation, but when we did finally get to Snooty he was no longer alive,” Rodgers said, before appearing to tear up at a news conference. “We’ve been greeting people at the front door to share the heartbreaking news with them as they come in. ... Aquarium staff is heartbroken.”

“We’re all quite devastated about his passing,” Brynne Anne Besio, the museum’s CEO, said in a statement on Sunday. “We’re reviewing what happened and will be conducting a full review of the circumstances. Snooty was such a unique animal and he had so much personality that people couldn’t help but be drawn to him. As you can imagine, I ― and our staff, volunteers and board members ― considered him a star. We all deeply mourn his passing.”

The aquarium will remain closed as the investigation continues. The manatee’s veterinarian of 20 years will be conducting the necropsy.

Longtime fans of Snooty expressed their shock at the news of his death, saying the manatee was a local celebrity.

“It was a little bit surreal coming here first. We were waiting for it to open and then about five or six minutes before the museum opened a staff person walked out and breaks the news to all the kids and parents standing outside waiting to head on in,” Josh Crotts told the Sarasota Herald Tribune. “It came as a shock to everybody, especially considering the timing.”

University of Exeter scientists found grey squirrels quickly remembered how to solve a problem they had not seen for almost two years.

The squirrels also quickly worked out how to use those skills in a redesigned version of the test.

"This might be why grey squirrels can survive very well in towns and cities," said Dr Pizza Ka Yee Chow, of Exeter's Centre for Research in Animal Behaviour.

"For example, they're very good at getting food from bird feeders.

"People may try different types of bird feeders to keep the squirrels away, but this research shows grey squirrels can not only remember tricks for getting food but can apply those skills in new situations."

In the study, five squirrels were given a task identical to one they had tried 22 months earlier, in which they had to press levers to get hazelnuts.

In that first experience, the squirrels improved with practice -- taking an average of eight seconds on their first attempt and just two seconds by the final time they tried it.

Trying again for the first time in 22 months, they took an average of just three seconds to get a hazelnut.

Grey squirrels are known to have good long-term memory -- they are "scatter-hoarders," collecting and hiding thousands of nuts every autumn.

"Previous research at Exeter has shown that their memory for the locations of hidden nuts is excellent," said co-author Professor Stephen Lea, of the University of Exeter.

But the new research demonstrates a "very different form of memory," said co-author Dr Théo Robert, also of the University of Exeter.

"This is not just remembering where things have been left, it shows they can recall techniques which they have not used for a long time," he said.

"It's also different from what we see in the wild because they're remembering things for longer than the few months of memory needed to find hidden food."

When presented with a version of the task that looked different but required the same technique to get hazelnuts, the squirrels showed a "neophobic" (fear of news things) response -- hesitating for more than 20 seconds on average before starting the task.

But once they started it took them just two seconds on average to get a hazelnut, showing that they were able to recall and apply the technique they learned in the previous form of the challenge.

No bells tolled when the last Catarina pupfish on Earth died. Newspapers didn't carry the story when the Christmas Island pipistrelle vanished forever.

Two vertebrate species go extinct every year on average, but few people notice, perhaps because the rate seems relatively slow -- not a clear and present threat to the natural systems we depend on. This view overlooks trends of extreme decline in animal populations, which tell a more dire story with cascading consequences, according to a new study that provides the first global evaluation of these population trends.

"This is the case of a biological annihilation occurring globally, even if the species these populations belong to are still present somewhere on Earth," said co-author Rodolfo Dirzo, a professor of biology.

Mapping loss

A 2015 study co-authored by Paul Ehrlich, professor emeritus of biology, and colleagues showed that Earth has entered an era of mass extinction unparalleled since the dinosaurs died out 66 million years ago. The specter of extinction hangs over about 41 percent of all amphibian species and 26 percent of all mammals, according to the International Union for Conservation of Nature (IUCN), which maintains a list of threatened and extinct species. This global disaster scene has the fingerprints of habitat loss, overexploitation, invasive organisms, pollution, toxification and climate change.

The new analysis, published in Proceedings of the National Academy of Sciences, looks beyond species extinctions to provide a clear picture of dwindling populations and ranges. The researchers mapped the ranges of 27,600 species of birds, amphibians, mammals and reptiles -- a sample representing nearly half of known terrestrial vertebrate species -- and analyzed population losses in a sample of 177 well-studied mammal species between 1990 and 2015.

Using range reduction as a proxy for population loss, the study finds more than 30 percent of vertebrate species are declining in population size and range. Of the 177 mammals for which the researchers had detailed data, all have lost 30 percent or more of their geographic ranges and more than 40 percent have lost more than 80 percent of their ranges. Tropical regions have had the greatest number of decreasing species while temperate regions have seen similar or higher proportions of decreasing species. Particularly hard hit have been the mammals of south and southeast Asia, where all the large-bodied species of mammals analyzed have lost more than 80 percent of their geographic ranges.

The study's maps suggest that as much as 50 percent of the number of animal individuals that once shared Earth have disappeared, as have billions of animal populations. This amounts to "a massive erosion of the greatest biological diversity in the history of Earth," the authors write.

"The massive loss of populations and species reflects our lack of empathy to all the wild species that have been our companions since our origins," said the new study's lead author, Gerardo Ceballos of the National Autonomous University of Mexico. "It is a prelude to the disappearance of many more species and the decline of natural systems that make civilization possible."

Cascading effects

Why does the loss of populations and biological diversity matter? Aside from being what the scientists call a prelude to species extinction, the losses rob us of crucial ecosystem services such as honeybees' crop pollination, pest control and wetlands' water purification. We also lose intricate ecological networks involving animals, plants and microorganisms -- leading to less resilient ecosystems and pools of genetic information that may prove vital to species' survival in a rapidly changing global environment.

"Sadly, our descendants will also have to do without the aesthetic pleasures and sources of imagination provided by our only known living counterparts in the universe," said Ehrlich.

In the meantime, the overall scope of population losses makes clear the world cannot wait to address biodiversity damage, according to the authors. They call for curbs on the basic drivers of extinction -- human overpopulation and overconsumption -- and challenge society to move away from "the fiction that perpetual growth can occur on a finite planet."

Dirzo is also the Bing Professor in Environmental Science. Dirzo and Ehrlich are senior fellows at the Stanford Woods Institute for the Environment.